German Foreign Minister and Vice-Chancellor Guido Westerwelle talks during a news conference in the headquarters of the Free Democratic Party, FDP, in Berlin, Germany, Sunday, April 3. Westerwelle announced that he will quit as party leader of the ailing FDP.

Because the party didn't disappear. In fact, in a turn of events reverberating across the country, on March 27 the Greens ended six decades of conservative rule in one of Germany's wealthiest states, completing their transformation from a radical protest party to a mainstream force shaking the traditional political order.

For the first time ever in Germany, and only the second time in all of Europe, a Green party is in charge of a state government. Capitalizing on a mix of nuclear aversion and local furor over a highly unpopular railway project in Stüttgart, the Greens doubled their representation to 24.2 percent in Baden Württemberg, stealing power from Merkel's ruling Christian Democratic Union (CDU). The Greens also tripled their representation in North Rhine Westphalia.

The election is among the first evidence of how Japan's nuclear crisis, sparked by the March 11 earthquake and tsunami, is causing political ripples worldwide. The election may foretell the rise of anti-nuclear parties in other nations, and serve as political warning to other leaders.

"The debate in connection with the Japanese nuclear plant of Fukushima was clearly what led to our defeat," Merkel said a day after the election. "My view of atomic energy has changed since the events in Japan."

Even Merkel's coalition partner, hitherto Germany's most pro-nuclear party, signaled a change of heart. "That was a vote over the future of atomic energy," said Mr. Westerwelle, who stepped down Sunday as FDP leader although he will remain foreign minister for now.

Green living

Proponents of an environmentally friendly lifestyle that minimizes energy use, the Greens represent society's new search for "postmaterialistic" values, says Gerd Langguth, a political scientist at the University of Bonn and former CDU parliamentarian.

The party's March 27 win was the culmination of many political fights since the 1960s, when the leaders of today's party were rebellious students trying to shake the political establishment. Coin­ci­dentally, their first victory against nuclear power was also in Baden Württemberg, in 1975, when 30,000 people staged a nine-month sit-in at what was to be Germany's first nuclear plant, in the hamlet of Wyhl.

"It felt like taking over a fortress," remembers Frank Baum. For many nights he traveled 15 miles from his hometown of Freiburg after work to sleep at the site. The protesters won the battle when the government canceled the facility, but they lost the war with the construction of 17 nuclear plants elsewhere in the nation. The event laid the foundation for the Green Party's March 27 win, turning Freiburg into the cradle of Germany's anti-nuclear movement and a model for environmental living. The city made its medieval center more pedestrian-friendly, laying down a lattice of bike paths and introducing a flat fee for tramways and buses. The city and region invested in alternative energy: Environmental research became a backbone of the region's economy, which today boasts Germany's largest solar-research center and an international center for renewable energy. In 2002, Frei­burg became the first large Ger­man city to elect a Green mayor (nearby Tübingen also elected a Green in 2008), forming a counterweight in the conservative region that Merkel's party ruled for 58 years.

"This Green model based on renewable energy and quality of life, and not only on GDP [gross domestic product] growth, is moving beyond the city to the regional level," says Miranda Schreurs, head of the Euro­pean Environmental and Sust­ainable Development Ad­vi­sory Councils, a Berlin-based network of advisers appointed by 16 European countries. "It has become mainstream."

The party's win in Baden Württemberg does not necessarily foretell Merkel's downfall in the 2013 federal election. The Green Party remains weak in east Germany, and its liberal stance on gay rights and immigration prevent it from appealing to conservative voters.

Merkel shifts on nuclear

Merkel is already backtracking on her pro-nuclear push. In early March, she called for a review of a plan she announced last fall to let Germany's nuclear reactors run for another decade. The plan, part of an ambitious road map for renewables to provide 80 percent of the nation's energy by 2050, would see a new nuclear fuel tax of ¤2.3 billion ($3.3 billion) annually.

"By international standards, the plan was very far-reaching," says Ms. Schreurs, who also heads the Environmental Policy Research Center at the Free University of Berlin. "Ger­many has pushed renewables harder than any country. But the fact that it pushed nuclear at the cost of a more rapid growth of renewable energy made the party not environmental enough."

Merkel's next test is in June with the end of the temporary shutdown of Germany's seven oldest nuclear reactors, begun after the Japan quake. Taking the plants off-line permanently could be a gesture toward the Greens.

"People are going to watch closely to see if actions now follow our words," said Horst Seehofer, a CDU leader.

Courts may have a say in the matter. Nuclear plant operators have threatened to sue the government for damages.

Unlike France, which maintains that nuclear energy will remain part of its energy future, Germany never disputed that it would end nuclear energy. The message of the election was clear: Do that faster.

Eyes now turn to Berlin, where Green coleader Renate Kün­ast could capitalize on the party's rising popularity in September's mayoral vote.

"The issues always associated with the Greens – climate change, nuclear threat – are going to be on the agenda for years, decades to come," says Gerd Mielke, a political researcher at the University of Mainz. "It's not going to be a once-in-a-while issue. It's going to provide a steady boost for the Greens."